Matt Groening, the creator of The Simpsons, was at The Grove’s Barnes & Noble in Los Angeles Wednesday night for a book signing. But not just any old book signing. Check out the signature he was giving out for the lucky purchasers of Simpsons World The Ultimate Episode Guide.

Simpsons World is a “comprehensive episode synopses for 20 seasons of The Simpsons, including 128 new gut-busting episodes never before covered! Stuff you may have missed! More screen shots than ever before! Over four hundred character profiles! Every chalkboard phrase Bart has ever written! Nifty new art throughout! Quotes and quips from all your favorite characters! Two or more jam-packed pages devoted to every episode!” [WOW! That is a lot of exclamation points!]

Matt Groening Hard at Work, Creating A Designer Bart Simpson Signature

“Matt Groening Nov. 17, 2010” Ay, caramba!